The relationship between directional freezing and freeze distillation, and how the same concept can be used to explain a story from 1890 that clear ice from a lake is more healthy than the water from which it came.
Is, or was, Directional Freezing a patentable process for making clear ice? That question was proposed on a trademark class exam this winter.
Testing out a new product that makes clear ice cubes using directional freezing, a process uncovered here on Alcademics.
Southwest Air's magazine features a method found here on Alcademics for making a clear ice ball and freezing objects inside it.